I have the exact same machine and I think that the remote lock/unlock trigger is the feature that I like the most. Last season it worked perfectly. This season it works but it developed a small quirk. One squeeze of the trigger is all that it takes to go from single wheel drive to dual wheel drive. However this year it takes around six trigger squeezes before it clicks from dual wheel drive to single wheel drive. Does that sound like a cable adjustment or lubrication issue?
Yours sounds more like a cable adjustment issue. Perhaps your cable has "broken in" and developed some slack. Lubricating the mechanism wouldn't hurt either. NLGI #2 lithium grease. Make sure you get it to penetrate into the dog and splines interior to the mechansim. Both are ery easy to do.
PK